The author cannot permit this book to go to press without acknowledging his indebtedness to the Education Committee of the United Synagogue for their encouragement and assistance. He is especially grateful to Dr. Julius H. Greenstone for his many helpful suggestions and his careful reading of the text, both in manuscript and in proof. To Dr. Cyrus Adler and Professor Mordecai M. Kaplan his thanks are also due in large measure for their aid in removing crudities and improving the form and content of the work.